C # Calculate the week by date,

C # Calculate the week by date,

In this example, kemlerson formula is used to calculate the day of the week Based on the date:

First, let's take a look at the definition of the kemlerson formula in Baidu Encyclopedia:
Kemlerson Formula
W = (d + 2 * m + 3 * (m + 1)/5 + y/4-y/100 + y/400) mod 7
In the formula, d indicates the number of days in the date, m indicates the number of months, and y indicates the number of years.
Note: There is a difference between the formula and other formulas:
The year and month are regarded as the 13 and 14 months of the previous year. For example, if the year-1-10 is used, the formula is converted to 2003-13-10.

1. Client (called Using ajax ):

$. Get ('caculateweekday', {y: 2016, m: 8, d: 9}, function (result ){
Alert (result );
})

2. Server:

1 /// <summary> 2 /// calculate the day of the week for a specific date. 3 /// </summary> 4 /// <param name = "y"> year </param> 5 // <param name = "m"> month </param> 6 // <param name = "d"> day </param> 7 // /<returns> </returns> 8 public string CaculateWeekDay (int y, int m, int d) 9 {10 if (m = 1 | m = 2) 11 {12 m + = 12; 13 y --; 14} 15 int week = (d + 2 * m + 3 * (m + 1)/5 + y/4-y/100 + y/400) % 7; 16 string weekstr = ""; 17 switch (week) 18 {19 case 0: weekstr = "Monday"; break; 20 case 1: weekstr = "Tuesday"; break; 21 case 2: weekstr = "Wednesday"; break; 22 case 3: weekstr = "Thursday"; break; 23 case 4: weekstr = "Friday"; break; 24 case 5: weekstr = "Saturday"; break; 25 case 6: weekstr = "Saturday"; break; 26} 27 return weekstr; 28}